Multi-copter drones provide aerial delivery of packages. A drone can be overloaded by a large package and under-utilized by a small package. Using only large drones would result in unnecessary expense for most packages. This can be addressed with a fleet of different sized drones. However, the need for a given sized drone at a given location at a given time is largely unpredictable, resulting in wasteful relocating of unloaded drones or often using local drones that are larger than needed.
U.S. Pat. No. 9,457,899 and US patent application 2016/0378108 teach connecting multiple drones side-by-side into a collective unmanned aerial vehicle (UAV) that can carry larger packages but can separate into smaller or single vehicles for smaller packages. This prior art teaches connecting the drones to each other by connectors on their propeller guards and related peripheral parts.